Process for polymerizing ethylene with lauryl methacrylate and n-vinyl-2-pyrrolidone



United States Patent PROCESS FOR POLYMERIZING ETHYLENE WITH LAURYL METHACRYLATE AND N-VINYL-2- PYRROLIDONE Stephan Ilnyckyj, Sarnia, Ontario, Canada, assignor to Esso Research and Engineering Company, a corporation of Delaware No Drawing. Filed June 4, 1964, Ser. No. 372,700

5 Claims. (Cl. 260-32614) The present invention is a continuation-in-part of Serial No. 131,722 :filed August 16, 1961, entitled, Improved Multi-Purpose Middle Distillate Additive.

The present invention is concerned with improved the flow of fuel at low temperatures and improving pour point characteristics of middle distillates, as well as improving the sediment characteristics of these fuels. More particularly the invention relates to the preparation of improved low cold test hydrocarbon fuels, in particular heating oils and diesel fuels, kerosene, aviation turbo-jet fuels, and other fuels that are subject to low temperatures. The preferred class of pour depressants of the present invention comprises copolymers of ethylene with lauryl methacrylate and particularly the terpolymer of ethylene with lauryl methacrylate and N-vinyl-Z-pyrrolidone.

With the increase in the use of hydrocarbon fuels of all kinds, a serious problem has arisen in areas frequently subject to low temperatures in the cold test characteristics of fuels. Particularly, serious problems have been en countered by heating oils and diesel and jet fuels that have too high a pour point, resulting either in distributional or operating difiiculties or both. For example, the distribution of heating oils by pumping or syphoning is rendered difficult or impossible at temperatures around or below the pour point of the oil. Furthermore, the flow of the oil at such temperatures through the filters cannot be maintained, leading to the failure of the equipment to operate.

It is, of course, well :known to add pour depressants to lubricating oils to lower the pour point. These lube oil additives, mostly high molecular weight organic compositions formed by alkylation of benzene or naphthalene or derivatives thereof or by polymerization of lower molecular weight methacrylates, or by condensation polymerization of various kinds, are not satisfactory in service with middle distillate and lighter fuels. Poor performance of these additives might possibly result from the structural differences between waxes occuring in lubricating oils and so-called middle distillates.

A wide variety of compounds have been found to be effective as pour point depressants for lubricating oil. Among the best known are Paraflow, Santopour, and Acryloid and their modifications. They are prepared either by condensing aromatic compounds with long chain parafiins, such as wax, or by condensing olefinic esters. It is generally consideredthat these pour depressants are effective in that in cooling an additive-containing oil, the hydrocarbon chain of the additive becomes incorporated into the crystal lattice of the separated wax, while the other part of the pour depressant molecule prevents the crystals from adhering together to form a gel structure. The failure of these additives to be effective in middle distillates may at least in part be due to the basic difference in the composition between the wax in lubrieating oils and that in middle distillate fuels.

It is, therefore, the principal object of the present ICE invention to set forth an improved pour depressant for middle distillate and lighter fuels. The boiling ranges of these oils are generally about 250 to 750 F.

The petroleum distillate fuels in which the additive materials of the invention are employed consist of a major proportion, at least 95%, of liquid hydrocarbons boiling at temperatures between about F. and about 750 F. These fuels include 'gasolines such as aviation, marine and automotive or motor gasolines, aviation turbo-jet fuels such as JP1, JP4 and JP-5 fuels, and diesel fuels such as marine, stationary and automotive diesel engine fuels.

Aviation turbo-jet fuel consists of .at least of a mixture of volatile hydrocarbons. It is defined by US. Military Specifications MIL-F-56l6 and MIL-#F-5624C. Its volatility is such that its end point does not exceed 572 F. Its viscosity is between 0.5 and 1.5 centistokes at F.

Diesel fuels as referred to in connection with the invention consist of at least 95% of a mixture of hydrocarbons boiling between 250 F. and 750 F. either by AST M Method D-86-56 when their end points do not exceed 600 F. or by ASTM Method D- 1-5 8-54. Diesel fuels are defined by ASTM Specification D-975-53T, and fall into Grades 1D, 2D, and 4D, in all of which the additive materials of the invention may be used. They have viscosities between 1.4 and 26.4 centistokes.

The liquid fuels in which the additives materials may be incorporated thus comprise at least 95% by weight of a mixture of hydrocarbons having a boiling range between the limits of 75 F. and 750 F. and a viscosity between the limits of 0.264 and 26.4 centistokes at 100 F.

In accordance with the present invention, an improved multipurpose additive is secured by utilizing copolymers of ethylene with lauryl methacrylate and particularly the terpolymers of ethylene with lauryl methacrylate and N-vinyl-2-pyrrolidone.

The superior additives of the present invention may be more fully understood by the following example illustrating the same.

Example 1200 mls. of benzene were pumped into a one gallon autoclave purged previously with ethylene. The autoclave was then heated to 300 F. and pressurized with ethylene to 900 p.s.i.g. In one operation, lauryl methacrylate was added alone and, in a second operation, lauryl methacrylate was added with N-vinyl-2-pyr-rolidone.. A di-t-butyl peroxide promoter was utilized. The injection rates were such as to introduce all of the monomers over a period of two to three hours and all of the peroxide over a period of three and one-quarter hours. The mixture was maintained at the reaction conditions for an additional 15 to 30 minutes after all of the reagents were added. During the reaction, the temperature of the mixture was controlled by a cooling coil and the pressure was maintained constant by supplying fresh ethylene from a cylinder through a pressure controlling valve. After the completion of the reaction, the product was discharged from the autoclave and stripped free of solvent (benzene) and the unreacted portions of the reagents.

The copolymers so obtained were evaluated in a reference oil boiling between 320-650 F. The pour depressant potency was measured by ASTM pour point test, and stabilizing potency was measured by Suspended Sediment Test, Potential Sediment Test and Accelerated Filter Plugging Test (Petroleum Processing, September 1956, p.

o .9 The results of these tests are shown in the following table.

TABLE.TERPOLYMER OF ETHYLENE, LAURYL METH- ACRYLATE AND N-VINYL-2-PYRROLIDONEA NEW POUR DEPRESSANT-STABILIZER FOR MIDDLE DISTIL- LATE FUELS Ethylene-lauryl Ethylene-lauryl methacrylate- Conditions methacrylate N-vinyl-Z-pyrrocopolymer lidone terpolymer Ethylene pressure to maintain,

p.s.i.g 900 900 Temperature, 'F.. 300 300 Lauryl methacrylate, Lauryl methacrylate, g./min 1. 4 N-vinyl-Z-pyrrolidone, g N l N-viuyl-2-pyrrolidone, g./1nin Nil 0. 42 Di-t-butyl peroxide, g 11.8 11.8 Di-t-butyl peroxide, gJmin. 0.06 0.06 Benzene, ml 1, 200 1, 200 Total reaction time, hrs. 3% 3% Product:

Yield, g 564 486 Consistency ASTM Pour of Ref. Oil, F

Wt. percent Polymer As in other appli- 8 catlons. 025 +5 Suspended Sediment, mg./100 ml.

- Nil 1.6 1. 6 i 0. 01- 0. 1 0. 4

Potential Sediment, rug/100 mlfi Nil 8. 7 8. 7 i 0. 01 1.8 1.8

Accelerated Filter Plugging PAD demerit of Nil 2. 6 2. 6 ref. oil. 0. 01 4. 5 1. 9

1 250 in 150 ml. of benzene.

Z 75 in 75 ml. of benzene.

3 Very viscous oil.

4 Oil filtered without a thermal treatment. Sediment reported in mg./l00 ml. of oil.

5 Oil kept for 16 hrs. at 210 F. and thou filtered. Sediment reported in rug/100 ml. of oil.

Bet: Petroleum Processing 11, No. 9, 145-9 (1956).

From the above it is apparent that the ethylene and lauryl methacrylate and particularly the ter-polymers of ethylene, lauryl methacrylate and =N-vinyl-2-pyrrolidone were very effective in improving the pour and improving the sediment characteristics of the fuel.

In general, it is preferred that the molecular weights of these polymers be in the range from about 700 to 3500, particularly in the range from about 1000 to 2000, as for example 1500. In the manufacture, it is preferred that the pressure be in the range from about 500 to 2000 p.s.i.g., preferably about 1000 p.s.i.g. The temperature during manufacture should be in the range from about 200 to 400 F., preferably about 300 1F. The amount of ethylene present in the polymer should vary in the range from 60 to 90 mole percent, preferably about 70 to 80 mole percent, as for example 75 mole percent. The amount of lauryl methacrylate present in the polymer should be in the range from 5 to 30%, preferably in the range from 10 to 20 mole percent, as for example 15 mole percent. In the tertiary polymer it is preferred that the amount of N-vinyl-Z-lpyrrolidone be in the range from about 2 to 20 mole percent, preferably in the range from about 8 to 12 mole percent, as for example 10 mole percent.

It is preferred that the amount of copolymer present in the fuel be in the range from about .001 to .5 wt. percent. A desirable concentration is below about 0.1%, as for example in the range from .01 to .05 wt. percent.

What is claimed is:

1. Process for the manufacture of an improved pour depressant and sediment improver which comprises introducing a benzene solvent into a reaction zone, maintaining the reaction zone at a temperature in the range from 200 to 400 =F., thereafter pressuriz-ing the same with ethylene to a pressure in the range from 500 to 2000 p.s.i.g., thereafter introducing into said recation zone a monomer selected from the group consisting of lauryl methacrylate and lauryl methacrylate and N-vinyl-Z- pyrrolidone and a promoter and maintaining said zone at said pressure and temperature conditions for a period of from two to three hours, thereafter recovering a polymer having a molecular weight in the range from 700 to 3500 therefrom.

2.. Process for the manufacture of an improved terpolyrner pour depressant and sediment improver having a molecular weight in the range from about 700 to 3500 which comprises introducing a benzene solvent into a reaction zone, maintaining the reaction zone at a temperature in the range from about '200 to 400 F, thereafter pressuring the reaction zone with ethylene to a pressure in the range from about 500 to 2000 p.s.i.g., thereafter introducing into said reaction zone a stream composition of lauryl methacrylate and N-vinyLZ-pyrrolidone and a promoter, maintaining said reaction zone at said pressure and temperature conditions for a period of from about two to three hours, thereafter recovering said terpolymer pour depressant and sediment improver.

3. Process as defined by claim 2 wherein said temperature is about 300 (F. and wherein said pressure is about 1000 p.s.i.g.

4. Process as defined by claim 2 wherein about 3 parts by weight of lauryl methacrylate are added per 1 part by weight of N-vinyl-Z-pyrrolidone.

5. Process as defined by claim :2 wherein the quantities of ethylene, la-uryil methacrylate and N-vinyl-2-pyrrolidone added to said reaction zone are such as to secure a terpolymer having about 60 to mole percent of ethylene, about 5 to 3 0 mole percent of lauryl methacryliate and about 2 to 20 mole percent of N-vinyil-2-pyrrolione.

References Cited by the Examiner UNITED STATES PATENTS 2,200,429 5/ 1940 Perrin et al. 2 60-80 3,089,897 5/1963 Balmer et a1. 2'60486 FOREIGN PATENTS 808,665 2/1959 Great Britain.

HENRY R. JILES, Acting Primary Examiner. J. TOVAR, Assistant Examiner. 

1. PROCESS FOR THE MANUFACTURE OF AN IMPROVED POUR DEPRESSANT AND SEDIMENT IMPROVER WHICH COMPRISES INTRODUCING A BENZENE SOLVENT INTO A REACTION ZONE, MAINTAINING THE REACTION ZONE AT A TEMPERATURE OF THE RANGE FROM 200* TO 400*F., THEREAFTER PRESSURIZING THE SAME WITH ETHYLENE TO A PRESSURE IN THE RANGE FROM 500 TO 200 P.S.I.G., THEREAFTER INTRODUCING INTO SAID REACTION ZONE A MONOMER SELECTED FROM THE GROUP CONSISTING OF LAURYL METHACRYLATE AND LAURYL METHACRYLATE AND N-VINYL-2PYRROLIDONE AND A PROMOTER AND MAINTAINING SAID ZONE AT SAID PRESSURE AND TEMPERATURE CONDITIONS FOR A PERIOD OF FROM TWO TO THREE HOURS, THEREAFTER RECOVERING A POLYMER HAVING A MOLECULAR WEIGHT IN THE RANGE OF 700 TO 3500 THEREFROM. 